Laboratory Experiments on the Interaction of a Buoyant Coastal Current with a Canyon: Application to the East Greenland Current
Laboratory Experiments on the Interaction of a Buoyant Coastal Current with a Canyon: Application to the East Greenland Current
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浮力沿岸流与峡谷相互作用的实验室实验：在东格陵兰洋流中的应用
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
C. Cenedese
中科院分区：
文献类型：
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作者：
D. Sutherland;C. Cenedese
本文介绍了一组实验室实验，重点是如何浮动的沿海流流过倾斜的底部与峡谷的相互作用，是什么控制分离，如果有的话，从上游峡谷弯曲的电流。结果表明，沿岸浮力流的分离取决于流宽W与水深曲率半径rc的关系。水流穿过峡谷的入口（即，分离的）对于W/RC。1，与以往的结果一致。本研究扩展了以前的工作，通过检查斜坡控制和表面捕获的电流，并使用特定的几何形状调查浮力电流峡谷的相互作用。作者发现，尽管海底摩擦在确定浮力锋的位置方面很重要，但由流动惯性驱动的分离过程甚至可以克服最强的测深影响。实验室结果应用于东格陵兰洋流（EGC），这是一种起源于北极的浮力流，观察到在丹麦海峡以南的两个分支中流动，表明EGC的路径受到切割大陆架的大峡谷的影响，因为海洋中的W/rc范围涵盖了实验室中观察到的范围。是什么原因导致形成的两个分支EGC结构下游的Kangerdlugssuaq峡谷（; 688 N，328 W）仍然不清楚，但潜在的机制进行了讨论。
This paper presents a set of laboratory experiments focused on how a buoyant coastal current flowing over a sloping bottom interacts with a canyon and what controls the separation, if any, of the current from the upstream canyon bend. The results show that the separation of a buoyant coastal current depends on the current width W relative to the radius of curvature of the bathymetry rc. The flow moved across the mouth of the canyon (i.e., separated) for W/rc . 1, in agreement with previous results. The present study extends previous work by examining both slope-controlled and surface-trapped currents, and using a geometry specific to investigating buoyant current‐canyon interaction. The authors find that, although bottom friction is important in setting the position of the buoyant front, the separation process driven by the inertia of the flow could overcome even the strongest bathymetric influence. Application of the laboratory results to the East Greenland Current (EGC), an Arctic-origin buoyant current that is observed to flow in two branches south of Denmark Strait, suggests that the path of the EGC is influenced by the large canyons cutting across the shelf, as the range of W/rc in the ocean spans those observed in the laboratory. What causes the formation of a two-branched EGC structure downstream of the Kangerdlugssuaq Canyon (;688N, 328W) is still unclear, but potential mechanisms are discussed.